Development and validation of metrics for assessment of ultrasound-guided fascial block skills

IntroductionLumbar disc surgery is painful. Few anaesthetists provide lumbar erector spinae block fordisc surgery and a need arises to provide training in order to conduct a randomisedcontrolled investigating pain relief after spinal surgery (NIHR153170).MethodsThe primary objective of the study was to measure the construct validity of a checklist forassessment of skills while performing lumbar and thoracic erector spinae fascial planeinjection in soft embalmed Thiel cadavers. Our secondary objectives were to assess the:construct validity of a global rating scale; construct validity of pectoral, serratus and fasciailiaca blocks in the same cadavers; correlation between the checklist and global rating scale;identify the most important checklist items and measure the variability of our observations.Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphiquestionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter,we validated the checklist by comparing the performance of 12 experts with 12 novices, eachperforming lumbar and thoracic ESP injections; fascia iliaca, serrato-pectoral (PEC II) andserratus injections, randomly allocated to the left and right sides of 6 soft embalmed Thielcadavers. Six expert, trained raters blinded to operator and site of block examined 120 videoseach.ResultsThe mean (95%CI:) internal consistency of the 11-item checklist for ESP injection was 0.72(0.63 – 0.79) and interclass correlation was 0.88 (0.82 – 0.93)The checklist showed construct validity for lumbar and thoracic erector spinae injection,experts vs novices (median (IQR [range]) 8.0 (7.0 to 10.0 [1 to 11]) vs 7.0 (5.0 to 9.0 [4 to 11]),difference 1.5 (1.0 to 2.5) P < 0.001). Global rating scales showed construct validity forlumbar and thoracic erector spinae injection, 28.0 (24.0 to 31.0 [7 to 35]) vs 21.0 (17.0 to24.0 [7 to 35]), difference 7.5 (6.0 to 8.5), P < 0.001.The most difficult items to perform were: identifying the needle tip before advancing theneedle and always visualising the needle tip. Instrument handling and flow of procedurewere the areas of greatest difficulty on the Global Rating Scale. Checklists and GRS scorescorrelated. There was homogeneity of regression slopes controlling for status, type ofinjection and rater. Generalizability analysis showed a high reliability using the checklist andGRS for all fascial plane blocks [(Rho (ρ2) 0.93-0.96): Phi (ϕ) (0.84 – 0.87)].ConclusionsWe showed construct validity of an 11-point checklist for fascial plane injection

Development and validation of metrics for assessment of ultrasound-guided fascial block skills☆

Background As few anaesthetists provide lumbar erector spinae block for disc surgery, there is a need to provide training to enable a randomised controlled trial investigating analgesia after painful spinal surgery (NIHR153170). The primary objective of the study was to develop and measure the construct validity of a checklist for assessment of skills in performing lumbar and thoracic erector spinae fascial plane injection using soft-embalmed Thiel cadavers. Methods Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphi questionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter, we validated the checklist by comparing the performance of 12 experts with 12 novices, each performing lumbar and thoracic erector spinae plane injections or fascia iliaca, serrato-pectoral (PEC II) and serratus injections, randomly allocated to the left and right sides of six soft-embalmed Thiel cadavers. Six expert, trained raters blinded to operator and site of block examined 120 videos each. Results The mean (95% confidence interval) internal consistency of the 11-item checklist for erector spinae plane injection was 0.72 (0.63–0.79) and interclass correlation was 0.88 (0.82–0.93). The checklist showed construct validity for lumbar and thoracic erector spinae injection, experts vs novices {median (interquartile range [range]) 8.0 (7.0–10.0 [1–11]) vs 7.0 (5.0–9.0 [4–11]), difference 1.5 (1.0–2.5), P<0.001}. Global rating scales showed construct validity for lumbar and thoracic erector spinae injection, 28.0 (24.0–31.0 [7–35]) vs 21.0 (17.0–24.0 [7–35]), difference 7.5 (6.0–8.5), P<0.001. The most difficult items to perform were identifying the needle tip before advancing and always visualising the needle tip. Instrument handling and flow of procedure were the areas of greatest difficulty on the global rating scale (GRS). Checklists and GRS scores correlated. There was homogeneity of regression slopes controlling for status, type of injection, and rater. Generalisability analysis showed a high reliability using the checklist and GRS for all fascial plane blocks (Rho [ρ2] 0.93–0.96: Phi [ϕ] 0.84–0.87). Conclusions An 11-point checklist developed through a modified Delphi process to provide best practice guidance for fascial plane injection showed construct validity in performing lumbar and thoracic erector spinae fascial plane injection in soft-embalmed Thiel cadavers